-- going concern tonight especially for the family of James Foley authorities believe they are closer by the hour to identifying his killer. ABC's chief investigative correspondent Brian Ross now on the new technology and the clues in the killer's eyes. British authorities today we're focusing on these neighborhoods in London. We're several hundred young Muslim men have been recruited to become some of the most brutal jihadist in the nicest organization. Including this man. No one time rapper known on YouTube has L -- Whose father is awaiting trial in New York for the al-Qaeda attacks on US embassies in Africa. This was an -- -- social posting two weeks ago from Syria -- the severed head of the Syrian soldier saying quote be heading is the only York. The only source of -- density. Is he very extreme and -- be manipulated version of Islam that says. You know I don't belong to any nation I'm only loyal to Islam. -- America is our principal enemy British authorities don't believe the rapper was the executioner of James Foley. But they say they are close to figuring out who he has United States is working closely with our partners around the -- including. The British. To identify that individual. Starting with the eyes of a hooded man. -- facial recognition experts created this likeness of the possible killer. Clean shaven and with a mustache. Other experts official and bloggers have been dissecting the desert background from the Foley -- identifying distinct topography -- growth. And rock formations to identify the precise area where the three remaining US hostages might be held. Believed to be near the crisis stronghold in the Syrian city of Rocca Rocca is about the safest -- treat for the Islamic state that currently exists it's. -- list here here's as the US carried out its unsuccessful attempt to rescue the American hostages. All three of them have been threatened with execution by -- including a young American woman human rights worker whose name has not been made public. Today her friends and colleagues said they have sent an open letter to ice is pleading for her life to be spared. All right Brian Ross reporting and again tonight thank you ongoing concern tonight especially for the family of James Foley authorities believe they are closer by the hour. To identifying his killer. ABC's chief investigative correspondent Brian Ross now on the new technology and the clues in the killer's eyes. British authorities today we're focusing on these neighborhoods in London. We're several hundred young Muslim men have been recruited to become some of the most brutal jihadist in the -- organization. Including this man. No one time rapper known on YouTube has L Jennings whose father is awaiting trial in New York. For the al-Qaeda attacks on US embassies in Africa. This was an Elgin a social posting two weeks ago from Syria -- in the severed head of the Syrian soldier saying quote be heading is the only York. The only source of identity. Is -- very extreme and are -- manipulated version of Islam that says. You know I don't belong to any nation I'm only loyal to Islam. -- America is our principal enemy British authorities don't believe the rapper was the executioner of James Foley. But they say they are close to figuring out who he has the United States is working closely with our partners around the world including. The British. To identify that individual. Starting with the eyes of the hooded man. Sense facial recognition experts. Created this likeness of the possible killer. Clean shaven and with a mustache. Other experts official and bloggers have been dissecting the desert background from the Foley tape identifying distinct topography plaque growth. And rock formations to identify the precise area where the three remaining US hostages might be held. Believed to be near the ice a stronghold. It was clear here that the US carried out its unsuccessful attempt to rescue the American hostages. All three of them have been threatened with execution by -- diocese including a young American woman human rights worker whose name has not been made public. Today her friends and colleagues said they have sent an open letter to ice is pleading for her life to be spared all right Brian Ross reporting and again tonight thank you.

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